A/c is not working, was told it was a module or something on the heater box, would you know what they are talking about and how much to fix?

Without knowing any specifics, it sounds like it is the climate control box, which is a valve that diverts the air flow over the heater core to give you heat, then when you want air conditioning , a valve moves a baffle to divert the fan air to pass over the A/C evaporator coil located in the car cabin.

The bad news is all this climate control valves and mini radiators are underneath the dash and there is a lot of labor getting the stuff out, especially if it needs replaced. You might luck out and it is just a linkage rod became disconnected. But count on at least 500 bucks if there is disassembly needed